Faculty Bibliography

Hematology is a clinical specialty with strong roots in the laboratory; accordingly, the lab can help solve perplexing clinical problems. This review highlights clinical-pathological conundrums addressed during my 35-year hematology career at McMaster University. Heyde syndrome is the association between aortic stenosis and bleeding gastrointestinal (GI) angiodysplasia where the bleeding is usually cured by aortic valve replacement; the chance reading of a neonatal study showing reversible deficiency of high-molecular-weight (HMW) multimers of von Willebrand factor (vWF) following surgical correction of congenital heart disease provided the key insight that a subtle deficiency of HMW multimers of vWF explains Heyde syndrome. The unusual immunobiology of heparin-induced thrombocytopenia (HIT)-a highly prothrombotic, antibody-mediated, anti-platelet factor 4 (PF4) disorder featuring rapid appearance and then disappearance (seroreversion) of the pathological heparin-dependent platelet-activating antibodies-permitted identification of key clinical features that informed development of a scoring system (4Ts) to aid in HIT diagnosis. Atypical clinical presentations of HIT prompted identification of heparin-independent anti-PF4 antibodies, now recognized as the explanation for vaccine-induced immune thrombotic thrombocytopenia (VITT), as well as VITT-like disorders triggered by adenovirus infection. Another unusual feature of HIT is its strong association with limb ischemia, including limb necrosis secondary to deep-vein/microvascular thrombosis (venous limb gangrene). The remarkable observation that supratherapeutic warfarin anticoagulation predisposes to HIT- and cancer-associated venous limb gangrene provided insight into disturbed procoagulant/anticoagulant balance; these concepts are relevant to microvascular thrombosis in critical illness (symmetrical peripheral gangrene), including a pathophysiological role for proximate "shock liver" (impaired hepatic synthesis of natural anticoagulants).

UNLABELLED:Heyde's syndrome is described as angio-dysplastic gastrointestinal (GI) bleeding in elderly patients with degenerative severe calcific aortic stenosis (AS), resulting in anaemia. It was first reported by Edward C. Heyde in 1958 and thus carried his name. Although this condition is considered to develop in 10-20% of severe AS, it is a less familiar entity in clinical practice. With the rising geriatric population in the communities, there is a proportionate increase in the incidence of AS and accompanying Heyde's syndrome. Heyde's syndrome has also been associated with hypertrophic cardiomyopathy, left ventricular assist device, ventricular septal defect, and patent ductus arteriosus. This article reports a case of Heyde's syndrome associated with congenital annular AS, successfully treated by aortic root enlargement and valve replacement. SUPPLEMENTARY INFORMATION/UNASSIGNED:The online version contains supplementary material available at 10.1007/s12055-023-01636-y.

Heyde's syndrome is a clinical entity that combines aortic stenosis, gastrointestinal angiodysplasia, and an acquired von Willebrand factor disorder. This syndrome is characterized by the association between aortic stenosis and recurrent gastrointestinal bleeding episodes, typically linked to angiodysplasias. Effective treatment requires addressing the underlying condition, specifically aortic stenosis, which leads to the structural destruction of coagulation proteins, resulting in the acquired von Willebrand factor disorder and perpetuating the bleeding. Therefore, managing gastrointestinal bleeding alone is insufficient. Although initially underestimated by physicians due to its nonspecific presentation and overlapping symptoms, this syndrome has significant implications for diagnosis and management, particularly in older adults. Many patients with Heyde's Syndrome are often misdiagnosed with unrelated gastrointestinal conditions until the association with aortic stenosis is identified. This diagnostic delay can lead to repeated hospitalizations, chronic anemia, and a decline in quality of life. Aortic valve pathology and coagulopathy should be actively suspected and investigated, directing treatment toward correcting the aortic stenosis. The objective of this case report is to highlight the importance of suspecting this syndrome in patients with valvular disease, such as aortic stenosis, and recurrent bleeding episodes, as these conditions may not always represent two independent problems, even if the patient has previously undergone valve replacement. This is demonstrated in the presented case, where a 74-year-old female patient with cardiovascular disease treated years earlier with valve replacement developed valve dysfunction, leading to new episodes of gastrointestinal bleeding. This illustrates the need to reevaluate the valve to prevent recurrent complications.

Heyde's syndrome (HS) represents an association between aortic stenosis and intestinal angiodysplasias, and it has been demonstrated that acquired von Willebrand disease plays a pivotal role in the pathophysiology of this syndrome. In patients with HS, von Willebrand factor deficiency represents an additional risk factor, further contributing to the risk of bleeding and anemia. We present the case of an 86-year-old patient diagnosed with HS and von Willebrand deficiency in 2018. Four years prior, the patient underwent surgical aortic valve replacement. Since then, she has been receiving chronic oral anticoagulation therapy with a vitamin K antagonist. The patient was admitted to the Internal Medicine Clinic due to semi-solid dark stools, diffuse abdominal pain, and asthenia. Upon examination, the patient presented with an altered general status and clinical signs suggestive of anemia. Laboratory findings revealed anemia with elevated INR and aPTT values. Colonic angiodysplasias were identified during a colonoscopy, although no sources of active bleeding were detected. On the 9th day of hospitalization, the patient experienced an episode of lower gastrointestinal bleeding. The pharmacological management was adjusted, and argon plasma coagulation was recommended. Following treatment of the angiodysplastic lesions, the patient's clinical evolution was favorable, with the correction of the anemia.

Primary gastric leiomyosarcoma is an exceptionally rare disease. This review covers 41 post-gastrointestinal stromal tumor (GIST) era gastric leiomyosarcoma cases that are supported by immunohistochemistry markers. Other spindle cell lesions are also excluded through histological and immunohistochemistry evaluations. The patients range from 3 to 82 years old, with an average age of 54.6 years. The male-to-female ratio is 1.4:1, from diverse geographic areas. Patients may experience abdominal symptoms, and tumor sizes vary between 1 cm and 22 cm. Morphologically, tumors originate from the muscularis propria or the muscularis mucosae, well-circumscribed with spindle cells arranged in fascicule. Tumoral cells exhibit positivity for smooth muscle markers while being negative for GIST markers and others. The mitotic index ranges from 2 to 500/50 high power field. Ki-67 index varies from 15% to 70%. Management typically involves gastrectomy and other appropriate treatments, with tumor recurrence being uncommon. 56% of patients are alive, with 5 patients dying from this disease. Statistical analyses conducted on post-GIST era cases reveal that a mitotic index of ≥100/50 high power field, tumor recurrence, metastasis, or positive lymph nodes significantly correlate with prognosis.

We present the case of an elderly man with a history of diastolic congestive heart failure, severe aortic stenosis and atrial fibrillation, who presented with fatigue, weakness, coffee ground emesis and black tarry stool. Haemoglobin was 68 g/L. Lactate dehydrogenase was elevated at 1038. Evaluation by cardiology and gastroenterology specialists revealed reflux oesophagitis and a mild hiatal hernia on oesophagogastroduodenoscopy, normal colonoscopy and small bowel series without obstruction. Capsule endoscopy identified angiodysplasia in the small intestine.The patient was diagnosed with Heyde's syndrome based on the triad of severe aortic stenosis, gastrointestinal bleeding from angiodysplasia and acquired von Willebrand syndrome. The patient underwent transcatheter aortic valve replacement, resulting in the resolution of symptoms.Heyde's syndrome represents a challenging clinical entity requiring a multidisciplinary approach for accurate diagnosis and management. Early recognition, prompt intervention and interdisciplinary collaboration are crucial in optimising patient outcomes.

The severity of aortic stenosis (AS) is associated with acquired von Willebrand syndrome (AVWS) and gastrointestinal bleeding, leading to anemia (Heyde's syndrome). We investigated how anemia is linked with AS and AVWS using the LA100 mouse model and patients with AS. Induction of anemia in LA100 mice increased transforming growth factor (TGF)-β1 activation, AVWS, and AS progression. Patients age >75 years with severe AS had higher plasma TGF-β1 levels and more severe anemia than AS patients age <75 years, and there was a correlation between TGF-β1 and anemia. These data are compatible with the hypothesis that the blood loss anemia of Heyde's syndrome contributes to AS progression via WSS-induced activation of platelet TGF-β1 and additional gastrointestinal bleeding via WSS-induced AVWS.

Purpose To investigate the accuracy and robustness of prostate segmentation using deep learning across various training data sizes, MRI vendors, prostate zones, and testing methods relative to fellowship-trained diagnostic radiologists. Materials and Methods In this systematic review, Embase, PubMed, Scopus, and Web of Science databases were queried for English-language articles using keywords and related terms for prostate MRI segmentation and deep learning algorithms dated to July 31, 2022. A total of 691 articles from the search query were collected and subsequently filtered to 48 on the basis of predefined inclusion and exclusion criteria. Multiple characteristics were extracted from selected studies, such as deep learning algorithm performance, MRI vendor, and training dataset features. The primary outcome was comparison of mean Dice similarity coefficient (DSC) for prostate segmentation for deep learning algorithms versus diagnostic radiologists. Results Forty-eight studies were included. Most published deep learning algorithms for whole prostate gland segmentation (39 of 42 [93%]) had a DSC at or above expert level (DSC ≥ 0.86). The mean DSC was 0.79 ± 0.06 (SD) for peripheral zone, 0.87 ± 0.05 for transition zone, and 0.90 ± 0.04 for whole prostate gland segmentation. For selected studies that used one major MRI vendor, the mean DSCs of each were as follows: General Electric (three of 48 studies), 0.92 ± 0.03; Philips (four of 48 studies), 0.92 ± 0.02; and Siemens (six of 48 studies), 0.91 ± 0.03. Conclusion Deep learning algorithms for prostate MRI segmentation demonstrated accuracy similar to that of expert radiologists despite varying parameters; therefore, future research should shift toward evaluating segmentation robustness and patient outcomes across diverse clinical settings. Keywords: MRI, Genital/Reproductive, Prostate Segmentation, Deep Learning Systematic review registration link: osf.io/nxaev © RSNA, 2024.

Reversion mutations that restore wild-type function of the BRCA gene have been described as a key mechanism of resistance to Poly(ADP-ribose) polymerase (PARP) inhibitor therapy in BRCA-associated cancers. Here, we report a case of a patient with metastatic castration-resistant prostate cancer (mCRPC) with a germline BRCA2 mutation who developed acquired resistance to PARP inhibition. Extensive genomic interrogation of cell-free DNA (cfDNA) and tissue at baseline, post-progression, and postmortem revealed ten unique BRCA2 reversion mutations across ten sites. While several of the reversion mutations were private to a specific site, nine out of ten tumors contained at least one mutation, suggesting a powerful clonal selection for reversion mutations in the presence of therapeutic pressure by PARP inhibition. Variable cfDNA shed was seen across tumor sites, emphasizing a potential shortcoming of cfDNA monitoring for PARPi resistance. This report provides a genomic portrait of the temporal and spatial heterogeneity of prostate cancer under the selective pressure of a PARP inhibition and exposes limitations in the current strategies for detection of reversion mutations.

INTRODUCTION:We aimed to compare outcomes of patients with first primary clinical T1a-bN0M0 NSCLC treated with surgery or stereotactic body radiation therapy (SBRT). METHODS:We identified patients with first primary clinical T1a-bN0M0 NSCLCs on last pretreatment computed tomography treated by surgery or SBRT in the following two prospective cohorts: International Early Lung Cancer Action Program (I-ELCAP) and Initiative for Early Lung Cancer Research on Treatment (IELCART). Lung cancer-specific survival and all-cause survival after diagnosis were compared using Kaplan-Meier analysis. Propensity score matching was used to balance baseline demographics and comorbidities and analyzed using Cox proportional hazards regression. RESULTS:Of 1115 patients with NSCLC, 1003 had surgery and 112 had SBRT; 525 in I-ELCAP in 1992 to 2021 and 590 in IELCART in 2016 to 2021. Median follow-up was 57.6 months. Ten-year lung cancer-specific survival was not significantly different: 90% (95% confidence interval: 87%-92%) for surgery versus 88% (95% confidence interval: 77%-99%) for SBRT, p = 0.55. Cox regression revealed no significant difference in lung cancer-specific survival for the combined cohorts (p = 0.48) or separately for I-ELCAP (p = 1.00) and IELCART (p = 1.00). Although 10-year all-cause survival was significantly different (75% versus 45%, p < 0.0001), after propensity score matching, all-cause survival using Cox regression was no longer different for the combined cohorts (p = 0.74) or separately for I-ELCAP (p = 1.00) and IELCART (p = 0.62). CONCLUSIONS:This first prospectively collected cohort analysis of long-term survival of small, early NSCLCs revealed that lung cancer-specific survival was high for both treatments and not significantly different (p = 0.48) and that all-cause survival after propensity matching was not significantly different (p = 0.74). This supports SBRT as an alternative treatment option for small, early NSCLCs which is especially important with their increasing frequency owing to low-dose computed tomography screening. Furthermore, treatment decisions are influenced by many different factors and should be personalized on the basis of the unique circumstances of each patient.